CareerCup

reverse(node n) {
  node prev = null;
  while(n != null) {
    node next = n->next;
    n->next = prev;
    prev = n;
    n = next;
  }
  return prev;
}

node *reverseList(node *start, node *prev)
{
	if (start == NULL)
		return prev;
	node *temp = start->next;
	start->next = prev;
	return reverseList(temp,start);
}

/* Call as reverseList(start,NULL); */

#include <stdio.h>
#include <malloc.h>

struct node {
node *next;
int data;
}*head;

node* reverseList(node *);
void printList(node *);
node* reverseListSimple(node *);

int main() {
node *temp, *prev=NULL;
//node *head = NULL;

for(int i=0;i<10;i++) {
// create temp node...
temp = (node *)malloc(sizeof(node));
temp->data = i;
temp->next = NULL;

if(head == NULL){
head = temp;
prev = temp;
}

prev->next = temp;
prev = temp;
}

//head = reverseList(head);
head = reverseListSimple(head);

printList(head);
}

node* reverseList(node *head) {
node *revHead = NULL;

if(head->next == NULL) return head;
revHead = reverseList(head->next);

head->next->next = head;
head->next = NULL;

return revHead;
}

node* reverseListSimple(node *head) {
node *cur=head, *next, *prev=NULL;

while(cur!=NULL){
next = cur->next;
cur->next = prev;
prev = cur;
cur = next;
}

return prev;
}

void printList(node *head) {
while(head!=NULL) {
printf("\n %d ",head->data);
head = head->next;
}
}

Node* link_reverse(Node* head)
{
if(head->next==NULL)
return head;
Node* new=link_reverse(head->next);
head->next->next=head->next;
head->next=NULL;
return new;
}